New trends in glaucoma surgery (Dr Ike K. Ahmed)

07Jun2011 from talk given 26Jun2010 1730hrs presented at the COS Annual Meeting in Quebec City by Dr Ike Ahmed. This is the last of the 201 COS glaucoma articles to be posted and just in time for the COS 2011 articles to begin to appear. Look for them in the months ahead as they will slowly apear as I finish editing them. Please note that the focus of the COS 2011 Glaucoma talks was on surgical treatment so there will be newer information on that portion of the blog.

Where will we be in next 5-10 years? 

  • Further reduction in Trabs and long tube shunts
  • More minimally invasive surgery
  • real time IOP assessment

Glaucoma specialists vs General Ophthalmologists?

With the development of minimally invasive surgery, we may see greater usage by general ophthalmologists instead of mostly glaucoma specialists.

We are seeing a 50% reduction in Trabs but increased Glaucoma drainage devices and Endoccyclophotocoagulation (ECP). Trabeculectomies still have their baggage but are very effective. Why are we seeing these changes in utilization?

  • SLT (widespread adoption early in the course of the disease)
  • phaco alone (cataract surgery alone often lowering IOP)
  • other procedures
  • early 1990s drugs (topical carbonic anhydrase inhibitors and prostaglandin analogs)

We know what phaco can do, even if open angle glaucoma but needs further study prospectively. ECP may offer mild to moderate reduction in IOP and can be effective for ACG to shrink the processes, combined with cataract surgery.

Exponential increase ExPress Mini-shunt

One advantage of the ExPress mini-shunt is that no iridectomy is performed. This should reduce inflammation and bleeding and prevent disruption of the blood-brain barrier.

MMC ExPress vs MMC Trab some data

  • early hypotony reduced with ExPress (Maris study)
  • DeJong study shows better IOP

Can minimally invasive surgery, done earlier, be the future?

We need to differentiate marketing vs evidence. Therefore, studies are ongoing to help prove whether these evolving techniqes are safe, effective and better than the alternatives that are available. One of the hurdles includes the cost.

Are some emerging technologies a ‘back to the future’ phenomenon?

Below are a few comments made about each of these devices that are updates on older concepts.


If suture tied right, can get mid to low teens


  • cutting right into the canal itself
  • for mild to moderate glaucoma, particularly if combined with cataract surgery

Similarly for the iStent

  • 1 stent 20%
  • 2 stents 35%
  • 3 about the same as with 2

Solex study halted due to lack of funding

Cypass shunt

- direct tube from the angle into the suprachoroidal space, a glorified cyclodialysis cleft as per the Solex plate

Patients may start having to pay for these interventions to cover the costs of these devices? (Already happening actually)